This invention relates to a hydrophobic, pyrogenically produced silica, to a process for the production thereof and to the use thereof.
It is known to compact hydrophilic, pyrogenically produced silica (EP0 280 851 B1). Disadvantageously, as tamped or bulk density increases, thickening action declines in a linear manner. Dispersibility also falls as density increases. This results in unwanted speckling. Thus, once compacted, a hydrophilic, pyrogenically produced silica may only be used for a limited number of applications.
It is therefore an object of the present invention to avoid the problems of compacted, hydrophobic, pyrogenically produced silica of the past.